SOUTH PACIFIC	FEBRUARY 9, 1998 NO. 6
	On Their Last Legs? New Zealand looks for ways to save its flightless birds, under threat from introduced predators By SIMON ROBINSON /AUCKLAND n adult kiwi's sturdy legs make up one third of its 2 kg body weight, and the flightless bird knows how to use them. Aggressive almost from birth--kiwi chicks hiss and snarl at threats--adults fight rats and possums, and males will kick each other to death to protect the eggs they incubate. Ornithologist John McLennan exploits the bird's feistiness to gather North Island brown kiwis for tagging in the Urewera National Park; he simply simulates a kiwi call on a plastic dog whistle and waits. "They think there's an intruder on their patch," he says. "They'll come galloping in and you can grab them as they run past." Too often, though, the batteries that power the tiny transmitters McLennan attaches to chicks' legs--as part of a Landcare Research and Department of Conservation program to track kiwis--outlive the birds. Settlement by Polynesians and then Europeans has brought new animals and land clearance, devastating the North Island brown and the three other kiwi species, along with many of New Zealand's other flightless birds. Now renewed efforts are under way to save the creatures. Says McLennan: "The big animals have been hammered by the peopling of the earth, but the smaller ones, there has to be room for them." Until 1,000 years ago, New Zealand's flightless birds were protected by accidents of geology and evolution that kept their island homes free of predators save other birds like giant hawks and owls. When their ancestral homeland separated from the supercontinent of Gondwana about 75 million years ago, it was home to many bird species but few mammals. While mammals came to dominate in other parts of the world, the only one to evolve in New Zealand was a native bat, which left birds alone. In the absence of mammals, says McLennan, "We had birds that became almost mammals themselves." The results fascinate zoologists and tourists alike. The kakapo, a bright green, flightless, nocturnal parrot , shares many features--such as soft plumage and fur-like discs around the eyes--with owls. The takahe, a member of the rail family, sports green and blue feathers and a bright red bill, and nests in the snow; it can grow to around 3 kg. But the most celebrated is the short--average height around 35 cm--squat kiwi. A distant relative of the cassowary, emu and ostrich, the kiwi lives on earthworms, spiders and fruit, sniffing out its food--it is one of few birds with a sense of smell--with a long, thin bill. Its image appears on everything from shoe polish to coins. "Travelers want something that says New Zealand," says Mary Koay, who sells kiwi-shaped toys, key rings and chocolates from Auckland shop Kiwi Souvenirs. "So they buy a kiwi." Tokens may one day be all that's left. Humans and the species they brought with them have decimated the populations of almost every type of flightless birds. The dogs and rats brought by Polynesians feasted on smaller birds, while Maori hunted the moa, some species of which grew 4 m tall. European settlement 200 years ago brought other predators, including cats, ferrets, pigs, possums and, most disastrously, the stoat, a kind of weasel introduced to control rabbits. "Stoats are a very efficient killer," says Murray Potter, a lecturer in ecology at Massey University. "And they live everywhere." By the late 19th century the moa was extinct. Others came close: the takahe was rediscovered in 1948 after not being seen for four decades. The kakapo, now found only on four tiny islands, has been named one of the world's 20 most endangered species by Britain's World Conservation Monitoring Centre. Fewer than 2,000 little spotted kiwis survive; the great spotted kiwi, which lives in upland areas of the South Island, numbers around 20,000; and the southern brown kiwi, endangered on the South Island, survives in similar numbers on stoat-free Stewart Island. A century ago there were more than 5 million North Island brown kiwis; today there are just 30,000, and numbers are shrinking by 6% a year. Still, there is reason for cautious optimism. Since DoC began intensive management and daily feeding of the kakapo in 1989, the adult mortality rate has fallen. Last April four chicks hatched in the wild: three survived. Deer control in the takahe's Fiordland home has allowed native vegetation to grow, and numbers in the Murchison Mountains, home to the largest wild population, have stabilized at around 120. Researchers have found that trapping predators in nearby areas can boost survival rates for North Island brown kiwi chicks from less than 5% to over 30%. "We're still learning how to do it, but the message is clear," says McLennan. "We've got to control mammals on a big scale year in, year out." DoC agrees, and has been creating predator-free reserves and rearing kiwis for release into the wild. The sense of urgency is spreading. DoC's recovery programs enjoy corporate support, schools have begun adopting local kiwi populations, and new housing estates bordering bush areas ban dogs and cats. But, says McLennan, "many New Zealanders still don't realise how unique our circumstances are. We had 70 million years of isolation, that's why we have curious animals like the kiwi. They just don't exist anywhere else." The humans whose coming almost doomed the flightless birds are now their greatest hope.
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